上一篇文章中写到在.net中实体类跟json格式的相互转换,在做具体转换时候,发现之前版本的jsonhelp对于日期类型的转换不全面。之前版本的jsonhelp中从实体类转换成json格式时候,将日期格式转成了时间戳的形式。在这里对这个jsonhelp做出了更新。以解决转换日期类型字段的问题。代码如下:
JsonHelp.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.Serialization.Json;
using System.IO;
using System.Text.RegularExpressions;
namespace JsonTest
{
class JsonHelp
{
public JsonHelp()
{
//
// TODO: Add constructor logic here
//
}
/// <summary>
/// 把对象序列化 JSON 字符串
/// </summary>
/// <typeparam name="T">对象类型</typeparam>
/// <param name="obj">对象实体</param>
/// <returns>JSON字符串</returns>
public static string GetJson<T>(T obj)
{
//记住 添加引用 System.ServiceModel.Web
/**
* 如果不添加上面的引用,System.Runtime.Serialization.Json; Json是出不来的哦
* */
DataContractJsonSerializer json = new DataContractJsonSerializer(typeof(T));
using (MemoryStream ms = new MemoryStream())
{
json.WriteObject(ms, obj);
string jsonString = Encoding.UTF8.GetString(ms.ToArray());
string pattern = @"\/Date((d+)+d+)\/";
MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertJsonDateToDateString);
Regex reg = new Regex(pattern);
jsonString = reg.Replace(jsonString, matchEvaluator);
return jsonString;
}
}
/// <summary>
/// 把JSON字符串还原为对象
/// </summary>
/// <typeparam name="T">对象类型</typeparam>
/// <param name="jsonString">JSON字符串</param>
/// <returns>对象实体</returns>
public static T ParseFormJson<T>(string jsonString)
{
T obj = Activator.CreateInstance<T>();
string pattern = @"d{4}-d{2}-d{2}sd{2}:d{2}:d{2}";
MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertDateStringToJsonDate);
Regex reg = new Regex(pattern);
jsonString = reg.Replace(jsonString, matchEvaluator);
using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(jsonString)))
{
DataContractJsonSerializer dcj = new DataContractJsonSerializer(typeof(T));
return (T)dcj.ReadObject(ms);
}
}
/// <summary>
/// 将Json序列化的时间由/Date(1304931520336+0800)/转为字符串
/// </summary>
private static string ConvertJsonDateToDateString(Match m)
{
string result = string.Empty;
DateTime dt = new DateTime(1970, 1, 1);
dt = dt.AddMilliseconds(long.Parse(m.Groups[1].Value));
dt = dt.ToLocalTime();
result = dt.ToString("yyyy-MM-dd HH:mm:ss");
return result;
}
/// <summary>
/// 将时间字符串转为Json时间
/// </summary>
private static string ConvertDateStringToJsonDate(Match m)
{
string result = string.Empty;
DateTime dt = DateTime.Parse(m.Groups[0].Value);
dt = dt.ToUniversalTime();
TimeSpan ts = dt - DateTime.Parse("1970-01-01");
result = string.Format("\/Date({0}+0800)\/", ts.TotalMilliseconds);
return result;
}
}
}
  测试代码:
using ConsoleApplication1.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
using (var db = new JooWMSContext())
{
var admin = db.Admins.Where(p => p.ID > 0).OrderBy(p => p.ID);
foreach (var ad in admin)
{
Console.WriteLine(JsonTest.JsonHelp.GetJson<ConsoleApplication1.Models.Admin>(ad));
}
Console.ReadKey();
}
}
}
}
  写测试代码时候 用到了EF ,这里推荐一个不错的工具。EF Power Tools 目前是beta4 版本。